Seems as if your amazon server has not enough RAM to start amavisd. You will either have to use a server with more RAM or you deactivate amavis (which will deactivate all spam and antivirus scanning) on that server.

I think I solved the problem. Running Ubuntu Perfect Server 64b 10.10 on an amazon microinstance has some issues. There are memory issues and amavis won't run properly so I removed it. I don't know why but I had to manually edit mail_user table from ispconfig database to set disableimap to "n" when it was "y". Then everything started working fine and I was able to use ispconfig control panel again. Once I fixed this I was able to create new mail accounts that worked fine from creation. It might have been the amavis issue that caused some misconfiguration of mail accounts.